Our major research interest is the control of cell division in E. coli and our investigation of this process relies chiefly on a modern molecular genetic approach. We have focused on a region of the chromosome which contains a cluster of cell envelope-cell division genes. In pursuit of our desire to study the expression of these cell division genes we have constructed a genetic and physical map of this region including the determination of the direction of transcription of the known genes. We are now at the stage where we can take advantage of our accumulated information and begin to explore the molecular aspects of the regulatory features of these cell division genes. The fact that a mutation which uncouples DNA synthesis and cell division maps in this region underscores the importance of these genes with respect to cell division. The first step is to construct operon fusions in which the promoters of the cell division genes are fused to the structural gene for -galactosidase. This will allow us to monitor the expression of these genes and to use the well developed lac genetic sytem to isolate regulatory mutants. The alternate fusions will also be constructed in which the lac promoter-operator region will be fused to the cell division structural genes. These fusions will be used to amplify the gene products. To fully understand the moleculer aspects of the regulation of these cell division genes it will be necessary to sequence the DNA from the wild type and the regulatory mutants that will be isolated. The sequence information will also be necessary in determining the novel overlap that exists between two of these cell division genes. We believe that by exploiting these methods we will begin to understand the regulatory features concerning the expression of these genes and what role the regulation of expression of these genes has in control of the cell cycle.